Also known as gun taps, the taps in these sets have spiral-point flutes that push chips ahead of the tap and out of through holes. Because they don't need to be reversed to prevent buildup, they produce threads more efficiently than standard taps and are suitable for production work. Taps have a square shank for compatibility with tap wrenches and tap holders for drill presses and milling machines. With a plug chamfer, they have 3-5 chamfered cutting threads, so they're suitable for start-to-finish tapping. All taps and drill bits are made of high-speed steel for use on most metal and plastic.